Statistics of the scalar dissipation rate using direct numerical simulations and planar laser-induced fluorescence data

▸ Scalar mixing was studied in similar turbulent flows with 3D DNS and 2D acetone PLIF. ▸ The DNS and experiment agree on the observed scalar statistics and their evolutions. ▸ The unconditional and conditional scalar dissipation rate PDFs are nearly lognormal. ▸ The ratio std. deviation/mean scalar dissipation grows from 0 initially to 2.3±20%. ▸ Similarly the conditional dissipation ratio grows to ∼1.4; both increasing with Re.